Non-transferable radio frequency identification label or tag

ABSTRACT

A Non-transferable Radio Frequency Identification (RFID) assembly for attachment to an article comprises a RFID module; and a antenna module coupled with the RFID module, the antenna module comprising a conductive layer, a substrate, and an adhesive modification layer between the conductive layer and the substrate, the adhesive modification layer configured such that when the assembly is attached to the article and attempt to remove the assembly will cause the substrate to release and leave the conductive layer intact.

RELATED APPLICATIONS INFORMATION

This Application claims priority under 35 U.S.C. 120 to U.S. patentapplication Ser. No. 12/573,825, filed Oct. 5, 2009, and entitled“Non-Transferable Radio Frequency Identification Label or Tag,” which inturn claims priority under 35 U.S.C. 119(e) to U.S. Provisional PatentApplication Ser. No. 61/102,645, filed Oct. 3, 2008, and entitled“Methods and Apparatus for Non-Transferable RFID Tag,” all of which areincorporated herein by reference in their entirety as if set forth infull.

BACKGROUND

1. Technical Field

The embodiments described herein are related to preventing the removalof a Radio Frequency Identification (RFID) label or tag once it has beenaffixed to an appropriate item in order to associate the label or tagwith another item.

2. Related Art

The embodiments described herein are related to Radio FrequencyIdentification (RFID) systems and more particularly to methods andapparatus to prevent unwanted and/or unwarranted access to informationstored on an RFID chip.

RFID is an automatic identification method, relying on storing andremotely retrieving data using devices called RFID tags or transponders.The technology requires some extent of cooperation of an RFID reader andan RFID tag. An RFID tag is an object that can be applied to orincorporated into a variety of products, packaging, identificationmechanisms, etc., for the purpose of identification and tracking usingradio waves. For example, RFID is used in enterprise supply chainmanagement to improve the efficiency of inventory tracking andmanagement. Some tags can be read from several meters away and beyondthe line of sight of the reader.

Most RFID tags contain at least two parts: One is an integrated circuitfor storing and processing information, modulating and demodulating aradio-frequency (RF) signal, and other specialized functions. The secondis an antenna for receiving and transmitting the signal. As the nameimplies, RFID tags are often used to store an identifier that can beused to identify the item to which the tag is attached or incorporated.But in today's systems, a RFID tag can contain non-volatile, possiblywritable EEPROM for storing additional data as well.

Most RFID systems use a modulation technique known as backscatter toenable the tags to communicate with the reader or interrogator. In abackscatter system, the interrogator transmits a Radio Frequency (RF)carrier signal that is reflected by the RFID tag. In order tocommunicate data back to the interrogator, the tag alternately reflectsthe RF carrier signal in a pattern understood by the interrogator. Incertain systems, the interrogator can include its own carrier generationcircuitry to generate a signal that can be modulated with data to betransmitted to the interrogator.

RFID tags come in one of three types: passive, active, and semi passive.Passive RFID tags have no internal power supply. The minute electricalcurrent induced in the antenna by the incoming RF signal from theinterrogator provides just enough power for the, e.g., CMOS integratedcircuit in the tag to power up and transmit a response. Most passivetags signal by backscattering the carrier wave from the reader. Thismeans that the antenna has to be designed both to collect power from theincoming signal and also to transmit the outbound backscatter signal.

Passive tags have practical read distances ranging from about 10 cm (4in.) (ISO 14443) up to a few meters (Electronic Product Code (EPC) andISO 18000-6), depending on the chosen radio frequency and antennadesign/size. The lack of an onboard power supply means that the devicecan be quite small. For example, commercially available products existthat can be embedded in a sticker, or under the skin in the case of lowfrequency RFID tags.

Unlike passive RFID tags, active RFID tags have their own internal powersource, which is used to power the integrated circuits and to broadcastthe response signal to the reader. Communications from active tags toreaders is typically much more reliable, i.e., fewer errors, than frompassive tags.

Active tags, due to their on board power supply, also may transmit athigher power levels than passive tags, allowing them to be more robustin “RF challenged” environments, such as high environments, humidity orwith dampening targets (including humans/cattle, which contain mostlywater), reflective targets from metal (shipping containers, vehicles),or at longer distances. In turn, active tags are generally bigger,caused by battery volume, and more expensive to manufacture, caused bybattery price.

Many active tags today have operational ranges of hundreds of meters,and a battery life of up to 10 years. Active tags can include largermemories than passive tags, and may include the ability to storeadditional information received from the reader, although this is alsopossible with passive tags.

Semi-passive tags are similar to active tags in that they have their ownpower source, but the battery only powers the microchip and does notpower the broadcasting of a signal. The response is usually powered bymeans of backscattering the RF energy from the reader, where energy isreflected back to the reader as with passive tags. An additionalapplication for the battery is to power data storage.

The battery-assisted reception circuitry of semi-passive tags leads togreater sensitivity than passive tags, typically 100 times more. Theenhanced sensitivity can be leveraged as increased range (by onemagnitude) and/or as enhanced read reliability (by reducing bit errorrate at least one magnitude).

The enhanced sensitivity of semi-passive tags place higher demands onthe interrogator concerning separation in more dense population of tags.Because an already weak signal is backscattered to the reader from alarger number of tags and from longer distances, the separation requiresmore sophisticated anti-collision concepts, better signal processing andsome more intelligent assessment of which tag might be where.

FIG. 1 is a diagram illustrating an exemplary RFID system 100. In system100, RFID interrogator 102 communicates with one or more RFID tags 110.Data can be exchanged between interrogator 102 and RFID tag 110 viaradio transmit signal 108 and radio receive signal 112. RFIDinterrogator 102 comprises RF transceiver 104, which containstransmitter and receiver electronics, and antenna 106, which areconfigured to generate and receive radio transit signal 108 and radioreceive signal 112, respectively. Exchange of data can be accomplishedvia electromagnetic or electrostatic coupling in the RF spectrum incombination with various modulation and encoding schemes.

RFID tag 110 is a transponder that can be attached to an object ofinterest and act as an information storage mechanism. In manyapplications, the use of passive RFID tags is desirable, because theyhave a virtually unlimited operational lifetime and can be smaller,lighter, and cheaper than active RFID tags that contain an internalpower source, e.g. battery. Passive RFID tags power themselves byrectifying the RF signal emitted by the RF scanner. Consequently, therange of transmit signal 108 determines the operational range of RFIDtag 110.

RF transceiver 104 transmits RF signals to RFID tag 110, and receives RFsignals from RFID tag 110, via antenna 106. The data in transmit signal108 and receive signal 112 can be contained in one or more bits for thepurpose of providing identification and other information relevant tothe particular RFID tag application. When RFID tag 110 passes within therange of the radio frequency magnetic field emitted by antenna 106, RFIDtag 110 is excited and transmits data back to RF interrogator 102. Achange in the impedance of RFID tag 110 can be used to signal the datato RF interrogator 102 via receive signal 112. The impedance change inRFID tag 110 can be caused by producing a short circuit across the tag'santenna connections (not shown) in bursts of very short duration. RFtransceiver 104 senses the impedance change as a change in the level ofreflected or backscattered energy arriving at antenna 106.

Digital electronics 114, which can comprise a microprocessor with RAM,performs decoding and reading of receive signal 112. Similarly, digitalelectronics 114 performs the coding of transmit signal 108. Thus, RFinterrogator 102 facilitates the reading or writing of data to RFIDtags, e.g. RFID tag 110 that are within range of the RF field emitted byantenna 104. Together, RF transceiver 104 and digital electronics 114comprise reader 118. Finally, digital electronics 114 and can beinterfaced with an integral display and/or provide a parallel or serialcommunications interface to a host computer or industrial controller,e.g. host computer 116.

With today's processing technology, and because they do not need abattery, conventional passive tags can be made very thin and very small.Consequently, they are finding more and more application in variousindustries for tracking and identification. For example, today's passivetags can be incorporated into a label that can be affixed tomerchandise, books, documents, passports or visas, car license plates orwindshields, etc. A problem that arises, however, is how to preventsomeone from removing such a label from the appropriate item andre-attaching or affixing it to another, e.g., counterfeit item?

Most conventional solutions to this problem involve designing the tag orlabel so that the tag is altered and will no longer function, or willnot be able to function optimally, if the tag or label is removed fromthe item to which it was originally affixed. One problem with thissolution is that the tag typically cannot be used to identify theoriginal item either.

SUMMARY

A non-transferable RFID tag or label that maintains its functionalitywhen someone attempts to remove the tag or label from the item to whichit is attached and that can indicate an attempt to tamper with the tagor label is disclosed herein

A Non-transferable Radio Frequency Identification (RFID) assembly forattachment to an article comprises a RFID module; and a antenna modulecoupled with the RFID module, the antenna module comprising a conductivelayer, a substrate, and an adhesive modification layer between theconductive layer and the substrate, the adhesive modification layerconfigured such that when the assembly is attached to the article andattempt to remove the assembly will cause the substrate to release andleave the conductive layer intact.

A Non-transferable Radio Frequency Identification (RFID) assembly forattachment to an article, comprises a RFID module; and a antenna modulecoupled with the RFID module, the antenna module comprising a conductivelayer, a substrate, and an adhesive modification layer between theconductive layer and the substrate, the adhesive modification layerconfigured such that when the assembly is attached to the article andattempt to remove the assembly will cause the substrate and theconductive layer to completely release from the assembly leaving theRFID module intact.

A Non-transferable Radio Frequency Identification (RFID) assembly forattachment to an article, comprises a antenna module; and a RFID modulecoupled with the antenna module, the RFID module comprising a substrate,a conductive layer on the substrate, a chip attached to the conductivelayer, and an adhesive modification layer between the conductive layerand the substrate, the adhesive modification layer configured such thatwhen the assembly is attached to the article and attempt to remove theassembly will cause the antenna module, the substrate, and theconductive layer to completely release from the assembly.

These and other features, aspects, and embodiments are described belowin the section entitled “Detailed Description.”

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and embodiments are described in conjunction with theattached drawings, in which:

FIG. 1 is a diagram illustrating an exemplary RFID system;

FIG. 2 is a diagram illustrating a two part RFID tag construction thatincludes an RFID module in accordance with one embodiment;

FIGS. 3A and 3B are diagrams illustrating the construction of anon-transferable RFID tag in accordance with various embodiments;

FIGS. 4A and 4B are diagrams illustrating the construction of anon-transferable RFID tag in accordance with various other embodiments.

DETAILED DESCRIPTION

FIG. 2 is a diagram illustrating an example RFID tag 200 that uses acapacitively coupled module construction. As can be seen, tag 200comprises a module 202 and a tag antenna 204. Module 202 comprises aloop 210 coupled with a chip 208 via conductive traces 212. In certainrespects, module 202 is itself a mini-tag that can transmit and receivesignals, typically in the Intermediate Frequency (IF) range; however,module 202 is designed to be couple with a plurality of boost antennas,such as antenna 204 illustrated in the example of FIG. 1.

Thus, antenna 204 and module 202 are configured such that they will,when combined, provide the appropriate operational characteristics, suchas frequency and range for a given application. It will be understood,therefore, that module 202 will include a matching circuit configured tomatch the combined impedance of antenna 204 and loop 210 with the inputsto chip 208. By using such a two part construction, cost reduction canbe achieved when producing multiple tag types, e.g., low, medium, andhigh dielectric tags, in even moderate quantities. This is because chip208 can be attached to module 202 and tested, either through directcontact or through loop 210 without the need to test the entire tag 200,which can be more cumbersome and costly.

Module 202 can be constructed on a substrate (not shown), such as aflexible plastic substrate, by, e.g., printing, screening, etc., loop210 and traces 212 on the substrate. For example, the substrate can be athin mylar film, e.g., nominally 0.003″ thick. Chip 210 can then beattached, e.g., via soldering, conductive adhesive, etc., to traces 212.Similarly, antenna 204 can be constructed on a substrate (not shown),e.g., via printing, screening, etc. Capacitive coupling can then be usedto couple loop 212 with antenna 204.

In capacitive coupling, module 202 is adhered with the, e.g., mylarsubstrate (not shown) of module 202 isolating the, e.g., conductive inkused to form loop 212 from the, e.g., conductive ink used to formantenna 204. This forms a capacitive region 206 where loop 212 overlapsantenna 204. The two pieces, i.e., module 202 and antenna 204 can bepressed and held together by an adhesive not shown. The RF energygathered from booster antenna 204 will transfer through the adhesive,through the RFID module 202 substrate (not shown) and conduct the RFenergy into RFID module 202. There is no need for any type of ohmic viabetween layers with this structure as in conventional devices.

By using this capacitive coupling technique, RFID modules can bemanufacturing in an efficient and cost-saving layout with high density.The same RFID module design could be used with many booster antennadesigns and styles. As long as the module can be mated with the boosterantenna and the capacitive coupling overlap area is present, boosterantennas of many types or sizes can be modified at will to fit thecustomer's application.

The capacitive coupling can prevent transfer of tag 200 from one deviceto another. FIG. 3A is a diagram illustrating one approach to preventingtransfer of such a tag. As can be seen, the tag or label illustrated inFIG. 3A consists of an antenna substrate 302 and a conductive layer 306.Conductive layer 306 can comprise the conductive pattern that formsantenna 204. An adhesive modification layer can be interposed betweensubstrate 302 and conductive layer 306.

Tag 300 can further comprise a module 316 comprising a substrate 310; aconductive layer 312, comprising the conductive pattern that forms loop210 and traces 212; and a chip 313. Module 316 can be attached to therest of the assembly via an adhesive layer 308. When module 316 isapplied over adhesive 308 to enable the performance gain offered by thecapacitive coupling of booster antenna 314, much of the surface area ofbooster antenna 314 will remain uncovered by module 316 and provide thesurface area for attachment to the customer's item.

Once this assembly 300 is applied to an item and held to that surface byadhesive 308, booster antenna 314 will provide all the adhesion surfacearea. If assembly 300 is removed from the original surface, the boosterantenna pattern 306 will be disturbed in the areas where adhesionmodification layer 304 was deposited, and the range performance gainoffered by the booster antenna will be altered.

However, module 316 does not have any adhesion modification or adhesiveapplied to it. When antenna 314 is disabled, or module 316 is removedfrom antenna 314, module 316 will return to its native performancecharacteristic, being functional for only a very short distance. Thiscan allow verification of the memory contents of chip 313. Further,module 316 can be used again. It should be noted, however, while module316 can be reused, tag or label 300 cannot simply be removed from theappropriate item and placed on another item.

FIG. 3B is a diagram illustrating another example nontransferableassembly 301 in accordance with another embodiment. In this example, anadhesive modification layer 311 is included between conductive layer 312and substrate 310, such that if someone attempt to remove assembly 301,loop 210, traces 212, or both will be disturbed so that RF energy cannotactivate chip 313 on module 316. With this construction, assembly 301can be rendered nonfunctional at any power level.

It can be desirable for the assembly to remain intact and operationalshould someone attempt to remove the assembly from the item to which itis attached. FIGS. 4A and 4B are diagrams illustrating further exampleembodiments of non-transferable tags or labels that remain operationalwhen someone attempts to remove them. In these embodiments, when theRFID tag liner or carrier is peeled away or removed from the authenticitem the transponder including antenna ink will remain intact on theauthentic item such that the performance is not adversely affected. TheRFID tag is therefore nontransferable and cannot be transferred to anunauthorized or counterfeit item because the carrier media thatoriginally supported the tag has been removed. The removal of thecarrier also serves to identify a physical tampering of the RFID tag.The carrier itself can also incorporate other security printing inks,fibers, and tamper evident features, such as holograms. The carrier canbe constructed from plastic, PVC, mylar, polycarbonate, teslin,demetalized foils, or other flexible substrates.

FIG. 4A is a diagram illustrating a multi-layer assembly 400 similar tothat illustrated in FIGS. 3A and 3B. The first layer 418 is the Boosterlayer. It begins with a blank substrate 402, which can be completelycoated with a release agent 404. Antenna 406 composes the next layer.Antenna 404 can be silver ink, copper, aluminum, etc. An adhesive 408coating then completes the first layer 418.

The second layer is the module layer 420. It also begins with a blanksubstrate 410. A module antenna 412 can then be attached to blanksubstrate 410. Antenna 412 can be formed by silver ink, copper,aluminum, etc. An IC chip 414 can then be attached to module antenna412.

The two layers 418 and 420 can be assembled by attaching the modulesubstrate 410 to booster layer 418 via adhesive 408. A protective liner416 can be placed atop the assembly in order to protect the exposedadhesive 408 that is not already covered by module substrate 410. Thiswill protect booster antenna 406 until it is placed on theoriginal/authentic item. Protective liner 416, if present, will beremoved to expose adhesive 408 before assembly 400 is placed on theoriginal or authentic item.

Module 420 can be coupled with antenna 418 via a conductive, inductive,or capacitive coupling technique. Module 410 and booster antenna 418must have some area where they overlap so that the capacitive or directcoupling of energy can occur. The RF energy gathered from boosterantenna 418 will transfer, e.g., through adhesive 408, through substrate410 and conduct the RF energy into RFID module 420.

In this embodiment, when someone attempts to remove assembly 400, theentire assembly 400 will release from substrate 404 and will remainaffixed to the item such that the performance is not adversely affected.The removal of substrate 402 from assembly 400 can be used as anindicator of a physical tampering with assembly 400. Thus, the boosterantenna adhesive 408 remains attached to the original or authentic item,along with the conductive trace pattern that forms antenna 406. Releaseagent 404 under the conductive trace pattern allows substrate 402 to beremoved without altering booster antenna 418 or module 420. However,since substrate 402, which acts as a carrier for assembly 400 isremoved, there is virtually no method to transfer assembly 400 to, e.g.,a counterfeit item.

FIG. 4B is a diagram illustrating a single layer assembly 401. Assembly401 comprises a release layer 404 applied to a substrate 402. An antenna406 can then be applied on top of release layer 404. Antenna 406 can beformed with silver ink, copper, aluminum, etc. An IC chip 414 can thenbe attached to antenna 406. A protective liner 416 can be placed atopthe assembly in order to protect the exposed adhesive 408. This willprotect the antenna 406 until it is placed on the original/authenticitem.

The operation of assembly 401 will then be similar to that describedwith respect to assembly 400. In other words, if someone attempts toremove assembly 401, substrate 402 will release leaving the remaininglayers intact, operational, and attached to the authentic item. Removalof substrate 402 will also indicate tampering with assembly 401.

While certain embodiments have been described above, it will beunderstood that the embodiments described are by way of example only.Accordingly, the systems and methods described herein should not belimited based on the described embodiments. Rather, the systems andmethods described herein should only be limited in light of the claimsthat follow when taken in conjunction with the above description andaccompanying drawings.

What is claimed is:
 1. A Non-transferable Radio Frequency Identification(RFID) assembly for attachment to an article, comprising: a antennamodule; and a RFID module coupled with the antenna module, the RFIDmodule comprising: a substrate, a conductive layer on the substrate, achip attached to the conductive layer, and an adhesive modificationlayer between the conductive layer and the substrate, the adhesivemodification layer configured such that when the assembly is attached tothe article and attempt to remove the assembly will cause the antennamodule, the substrate, and the conductive layer to completely releasefrom the assembly.
 2. The Non-transferable RFID assembly of claim 1,wherein the antenna module comprises a substrate, and a conductive layeron the substrate.
 3. The Non transferable RFID assembly of claim 1,wherein the RFID module conductive layer comprises a conductive loop. 4.The Non transferable RFID assembly of claim 1, further comprising anadhesive layer between the RFID module and the antenna module forcoupling the RFID module to the antenna module.
 5. The Non transferableRFID assembly of claim 1, wherein the antenna module and the RFID moduleare capacitively coupled.
 6. The Non transferable RFID assembly of claim2, wherein the antenna module conductive layer comprises an antennapattern.
 7. The Non transferable RFID assembly of claim 3, wherein theantenna module conductive layer comprises an antenna pattern, andwherein the chip is impendence matched with the combination of theconductive loop and antenna pattern.